After Millennia of Heavy Use, Mercury Gets the Boot

For at least two thousands years, the element mercury has fascinated a bevy of ancient civilizations, from the Hindus to the Chinese, to the Greeks and Romans. But an international resolution passed over the weekend means that mercury’s saga will soon be coming close to an end.

Two centuries before the turn to the Common Era, the first Emperor of China, Ying Zheng, went to his grave surrounded by an army of clay soldiers—a force of troops and horses, chariots and weapons counting 8,000 strong. Nearby, says National Geographic, were “replicas of the area’s rivers and streams made with mercury flowing to the sea through hills and mountains of bronze. Precious stones such as pearls are said to represent the sun, moon, and other stars.” The great emperor died, it is thought, of mercury poisoning—the unfortunate aftermath of his consuming the toxic metal in a bid for immortality.

Centuries later, hordes of would-be alchemists, including Sir Isaac Newton, experimented with the liquid metal in a bid to turn lead into gold through the fabled Philosopher’s Stone.

Right up through to the early 20th century, says Julie Sloane for Dartmouth College, mercury’s role in medicine continued–the element was used as a treatment for the then-rampaging syphilis.

In the 19th century, says the American Chemical Society, “Mercurial disease was common among hatters and included such symptoms as tremors, irritability, and mental instability.”

To make felt, hatters separated fur from the skin of small animals in a process called carroting. In this process, the secondary nitrous gas released from mercury (II) nitrate caused the fur to turn orange, lose shape, and shrink. The fur also then became darker, coiled, and more easily removed.

The true industrial effects of mercury exposure, dramatized in Lewis Carrol‘s 1865 book Alice’s Adventures in Wonderland, inspired the phrase “Mad as a hatter.”

The 1970s marked a bit of a turning point in some people’s perception of mercury, when the “Poisoning of Minamata” began to make headlines, says University of Minnesota philosopher of science Douglas Allchin. In 1956, says Allchin, an “apparent epidemic broke out,” where “people would stumble while walking, not be able to write or button their buttons, have trouble hearing or swallowing, or tremble uncontrollably.” The disease was traced to the mass mercury-poisoning of the residents of Minimata Bay, Japan:

Minamata is located on the Western coast of Kyushu, Japan’s southernmost island…. Its disturbing story begins, perhaps, in the 1930s, as the town was continuing to shed its heritage as a poor fishing and farming village. In 1932 the Chisso Corporation, an integral part of the local economy since 1907, began to manufacture acetaldehyde, used to produce plastics. As we know now, mercury from the production process began to spill into the bay. Though no one knew until decades later, the heavy metal became incorporated into methyl mercury chloride: an organic form that could enter the food chain.

To this day, mercury is a common component of a wealth of consumer and industrial products, everything from batteries and dental fillings to paint and cosmetics, says the Environmental Protection Agency. But this, says Science Insider, is soon to change, with the signing by 140 countries of the Minimata Convention. The agreement “will require its signatory nations to phase out the use of mercury in certain types of batteries, fluorescent lamps, and soaps and cosmetics by 2020,” draw down coal-fired power plants’ and cement factories’ mercury emissions, and reduce the use of mercury in gold mining.

More from Smithsonian.com:
Mystery at Sea – How mercury gets into tuna and other fish in the ocean has scientists searching from the coast to the floor
Sugar-coated Mercury Contamination

Colin Schultz | | READ MORE

Colin Schultz is a freelance science writer and editor based in Toronto, Canada. He blogs for Smart News and contributes to the American Geophysical Union. He has a B.Sc. in physical science and philosophy, and a M.A. in journalism.